Philae Has Landed: Here Are the 5 Things It Could Teach Us About the Cosmos

Rosetta & Philae's long journey to land on Comet 67P/Churyumov-Gerasimenko is a historical first, and an achievement that could tell scientists all kinds of new things about these icy, dusty, celestial wanderers.

1. Did Earth's Water Come From Comets?

1. Did Earth's Water Come From Comets?

Scientists have known for more than a century that comets are made of mostly rock and frozen water. Which made them wonder: Did our planet's own water come from comet impacts early in Earth's history?

Rosetta and Philae will elucidate this question by giving us a crystal clear picture of the makeup of comet C-G's ice. Because ice, just like liquid water, can be composed of different flavors of hydrogen and oxygen called isotopes, we'll soon be able to compare how much this comet's water varies compared to what researchers think was the makeup of Earth's early ocean water.

01Of05

2. What Exactly Are Comets Made Of?

2. What Exactly Are Comets Made Of?

There's a big difference between spying something 4 billion miles away through a telescope and actually landing on the thing with a drill and scientific instruments. Researchers have gathered a rough idea of comets' structure and composition from afar, but Rosetta and Philae will soon be giving us unprecedented detail about what minerals, organics, and other compounds your average comet is made of. This is important, because knowing C-G's makeup will help us answer big questions about when and where comets come from.

1. Did Earth's Water Come From Comets?

Scientists have known for more than a century that comets are made of mostly rock and frozen water. Which made them wonder: Did our planet's own water come from comet impacts early in Earth's history?

Rosetta and Philae will elucidate this question by giving us a crystal clear picture of the makeup of comet C-G's ice. Because ice, just like liquid water, can be composed of different flavors of hydrogen and oxygen called isotopes, we'll soon be able to compare how much this comet's water varies compared to what researchers think was the makeup of Earth's early ocean water.

2Of5

2. What Exactly Are Comets Made Of?

There's a big difference between spying something 4 billion miles away through a telescope and actually landing on the thing with a drill and scientific instruments. Researchers have gathered a rough idea of comets' structure and composition from afar, but Rosetta and Philae will soon be giving us unprecedented detail about what minerals, organics, and other compounds your average comet is made of. This is important, because knowing C-G's makeup will help us answer big questions about when and where comets come from.

Halley Multicolor Camera Team, Giotto Project, ESA

Advertisement - Continue Reading Below

3Of5

3. How Old Are Comets?

As far as we've been able to decipher, comets appear to be the oldest objects we've ever seen in the solar system. Some scientists believe they predate our own home world and Sun, possibly originating from before the primordial chaos that created both. This means that by studying comets up close (chiefly their chemical composition) we may be able to find a hidden record of the various physical and chemical processes that occurred in the early stages of our solar system—or before.

4. How Did Comets Form, and Where Are They From?

Two of the biggest outstanding questions about comets are also the most basic. Where do these ancient, icy wanderers of the night's sky hail from, and what caused them to form and shoot out toward our solar system? Rosetta and Philae may not be able to provide a definitive answer, but their close study of the age and composition of C-G may help researchers rule out a few theories, or surprise us and spawn new ones.

Advertisement - Continue Reading Below

5Of5

5. Could Comets Have Brought Life to Earth?

It's not science fiction. Exogenesis (or panspermia)—the idea that life may have first come to Earth by hitchhiking upon a cosmic wanderer like a comet—is a serious scientific hypothesis. But the truth of this theory may hang on whether or not Philae finds organic molecules—the very ones that we know can build life—or even life itself.